Vir, GSK plan to seek emergency use nod for COVID-19 antibody therapy

Covid treatment breakthrough as trial finds monoclonal antibody drug cuts risk of infected patients dying by up to 85%

  • GlaxoSmithKline’s Vir-7831 monclonal antibody treatment was in Phase 3 trials 
  • It was so successful in treating Covid that scientists have stopped them early
  • Monoclonal antibody treatment takes immune molecules from Covid patients 

A monoclonal antibody drug cuts the risk of Covid patients dying or being admitted to hospital by up to 85 per cent, trial results have found. 

GlaxoSmithKline’s Vir-7831 drug, which is made for people with mild to moderate illness, has been so successful in trials that scientists have stopped them early. 

The UK-based firm and its partner, Vir Biotechnology, plan to immediately seek an emergency use authorisation in the US and approval in other countries, including potentially in the UK.

Monoclonal antibodies are lab-produced molecules that mimic human antibodies — disease-fighting proteins made by the immune system.

The global phase three clinical trial based its analysis on data from 583 patients at risk of being admitted to hospital.

There are currently three monoclonal antibody treatments that have been given emergency use authorisation in the US, with US-based pharmaceutical firm Eli Lilly manufacturing both bamlanivimab and etesevimab.

And another treatment made by Regeneron in the US was used on Donald Trump on October 2 last year during his Covid battle and may have helped him recover.

None have so far been approved in the UK, where the only hospital treatments for Covid patients are steroids for people already on ventilators or with dangerously low oxygen levels.

Vir-7831 works in two ways — by blocking the virus’s entry into healthy cells and also clearing infected cells.

A separate lab study has found Vir-7831 is effective against the main current Covid variants, including the Kent, South African and Brazilian strains, the firm said.

Vir-7831 is designed to be given as an IV drip into a vein.

GlaxoSmithKline’s Vir-7831 monoclonal antibody drug cuts the risk of Covid patients dying or being admitted to hospital by up to 85 per cent, trial results have found

Monoclonal antibodies are lab-produced molecules that mimic human antibodies — disease-fighting proteins made by the immune system

Dr Hal Barron, GSK’s chief scientific officer, said: ‘We are pleased that this unique monoclonal antibody was able to bring such a profound benefit to patients.

‘We look forward to the possibility of making Vir-7831 available to patients as soon as possible and to further exploring its potential in other settings.’

A trial using the drug in very sick patients in hospital was stopped last week owing to lack of benefit, however. 

The treatment is different to a vaccine because it does not train the body to develop immunity against the illness.

Vaccines usually inject someone with a part of the virus so their body can learn how to fight it in a safe environment by being exposed to it for real. 

The antibody therapy would be limited and would not lead to the body making more of its own antibodies.

A mocolonal antibody treatment made by Regeneron in the US was used on Donald Trump (pictured returning to the White House after recovering from Covid) on October 2 last year during his Covid battle and may have helped him recover

The results come after US drugmaker Eli Lilly yesterday said its combination of two synthetic antibodies was similarly effective.

Results showed its antibody treatment reduced hospitalisations and deaths in high-risk patients recently diagnosed with Covid by 87 per cent.

The results came from a phase three clinical trial of 769 people aged 12 and over with mild-to-moderate Covid, who were considered high-risk because of their age or underlying conditions.

Among them, 511 received the combination treatment, which is already authorized for emergency use in the US, and 258 received a placebo.

There were four hospitalisations and no deaths in the treatment group, while four people died in the placebo group and 11 were hospitalised. This represented a statistically significant risk reduction of 87 per cent.

The new results add to previous data reported by the company in January which used different dosing levels for the two antibodies and also showed a drastic risk reduction.

The new results came with 700mg of the antibody bamlanivimab and 1400mg of etesevimab while the previously reported data used a combination of 2800mg of each.

‘The consistent results observed in multiple cohorts of this trial over several months, even as new strains of Covid have emerged, indicate bamlanivimab with etesevimab maintains its effects against a range of variants,’ said Daniel Skovronsky, the company’s chief scientific officer.

Monoclonal antibodies are lab-made versions of the body’s natural infection-fighting defenses.

Our bodies develop these proteins in response to pathogens, and vaccines train the immune systems to be prepared without encountering the live microbe itself.

Giving people ready-made antibodies can help those who are at high risk of severe disease because of weak immunity or underlying conditions.

But their uptake has been limited by factors including a lack of patient interest, and not enough staffing and places inside hospitals to administer them.

It can also be challenging to identify candidates who are at high risk but haven’t yet progressed to severe Covid.

Serious allergic reactions have been observed in some people who were given the intravenously infused therapy. 

WHAT ARE MONOCLONAL ANTIBODIES AND DO THEY WORK? 

Monoclonal antibody therapy is a form of immunotherapy that uses monoclonal antibodies (mAb). 

It’s given as an injection under the skin or through a drip into a vein. 

The treatment works in many different ways. It can work in a vaccine-like way, protecting a patient from severe disease, or can help to stimulate the patient’s immune system to attack antigens. 

Hybridoma technology is one method for producing large numbers of monoclonal antibodies – identical antibodies that are clones of a unique parent cell.

The process starts by injecting an animal, such as a mouse, with an antigen that provokes an immune response.  

B cells produces antibodies that bind to the antigen. These antibody producing B-cells are then harvested and used to culture more antibodies. 

The monoclonal antibodies are screened against their ability to work, with initial experiments in animals.

GlaxoSmithKline Vir-7831

Does it work?

A global phase three clinical trial of 583 patients showed the drug cuts the risk of infected Covid patients dying by up to 85 per cent.

A separate lab study has found Vir-7831 is effective against the main current Covid variants, including the Kent, South African and Brazilian strains, the firm said. 

Has it been approved?

Not yet, but GSK plans to immediately seek an emergency use authorisation in the US and approval in other countries.

Eli Lilly bamlanivimab 

Does it work?

Phase three clinical trials in October showed bamlanivab was effective in treating mild-to-moderate Covid patients. 

But research released in February suggests the drug is ineffective against the South African and Brazilian Covid strains.

Has it been approved?

The US Food and Drug Administration gave emergency use authorisation to bamlanivimab for the treatment of mild-to-moderate Covid in adult and pediatric patients in November last year.

Eli Lilly etesevimab

Does it work?

A phase three clinical trial of 769 people aged 12 and over with mild-to-moderate Covid yesterday showed etesevimab to be effective in treating Covid when administered in combination with bamlanivimab.

The trial included people who were considered high-risk because of their age or underlying conditions. 

Has it been approved?

The US Food and Drug Administration gave emergency use authorisation for bamlanivimab and etesevimab administered together for the treatment of mild to moderate Covid in adults and pediatric patients.

Etesevimab has not been given authorisation for treatment on its own. 

Regeneron 

Does it work? 

Regeneron’s coronavirus antibody drug reduces the risk of getting Covid after exposure by 50 percent, January trial results suggest.

The treatment prevented all of the 186 people who got the drug after being exposed to coronavirus from developing symptomatic Covid. 

Former US President Donald Trump was given the drug as part of his successful treatment for Covid in November.

Has it been approved? 

Regeneron’s cocktail has been given emergency use authorisation by the FDA. 

Although it wasn’t approved, the company agreed to supply a single dose for Mr Trump at the request of his physician under ‘compassionate use’ provisions.

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